"Devrin Talen" <dc...@cornell.edu> writes: > To block on accesses to a file until it actually has > data for you try reading up on the `select` call: > > % man 2 select
That would be great because that is exactly what I need. However I didn't get it to work. I always get "No data." for the below code, but it doesn't wait for the timeout, it is just no data instantly on every iteration. Does select(2) really block until there is data, or does it block until it is possible to read the fd? The whole program: http://user.it.uu.se/~embe8573/llc-select/ // select fd_set rfds; FD_ZERO(&rfds); FD_SET(0, &rfds); FD_SET(fd, &rfds); int retval; long long old_count = -1; long long count = 0; struct timeval tv; tv.tv_sec = 0; tv.tv_usec = rate*1000; while (count < max_misses) { retval = select(fd + 1, &rfds, NULL, NULL, &tv); if (retval == -1) { std::cerr << "Can't select()!" << std::endl; } else if (retval) { std::cout << "Data available! "; read(fd, &count, sizeof(count)); if (count != old_count) { std::cout << "LLC misses: " << count << std::endl; } } else { std::cout << "No data." << std::endl; } } -- underground experts united -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/877fzqxxva....@debian.uxu
